Question

Найдите (5*a-b)/(a+3*b) при b/a= -3

Answer 1

(5а - b)/(a + 3b) = (a(5 - b/a))/(a(1 + 3b/a)) = (5 - b/a)/(1 + 3b/a)
Если b/a = -3, то (5 - b/a)/(1 + 3b/a) = (5 - (-3))/(1 + 3 × (-3)) = (5 + 3)/(1 - 9) = 8/(-8) = -1